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Friday, 3 May 2013

Retroperception: Problems for Enactivism?

Yes,
it’s consciousness again. Or rather, perceptual experience. This time, some
musings about what the newly-minted cognitivist phenomenon of retroperception (see this Mindhacks post for a summary)
might mean for enactivist theories of perceptual experience.

Before
we begin, let us take note of a critique levelled against cognitivism by the
enactivist Thompson (2007) - that the representationalist, information
processing account has replaced the mind/body problem with a new mind/mind
problem. This is to say, how and why does hidden cognitive processing, which
goes on ‘in the dark’, yield conscious experience, and how can we take
seriously a body of thought which so often seems to end up pushing our experience
of the world towards an epiphenomenal status? Contrary to representationalist
accounts, enactivism denies that human beings experience an ‘external’ world
indirectly via some kind of 'internally constructed' model and suggests instead
that, through our sensorimotor systems, we have a form of direct access that
constitutes the ‘bringing forth’ of a subjective, experiential world. Therefore, like enactivism's forerunner phenomenology, the description of our experiential world could be seen as enactivism’s
prime concern. This must include explaining the perceptual quirks that have been
comprehensively documented by cognitive psychologists. In their influential
2001 article, Noe and O’Reagan do a good job of explaining various peculiar
facets of visual experience within their own theoretical framework.

What,
then, would Thompson or Noe and O’Reagan make of the newly documented
phenomenon of retroperception? According to this paper by Claire Sergent et al,
experimental participants perceived a pattern when their attention was directed
to the area as much as 400 milliseconds after the pattern had in fact
disappeared. The implications of this are that participants consciously
perceived what was no longer there, and from this, that we (within certain very
limited temporal parameters) routinely perceive what is no longer there. As
Mindhacks puts it, ‘This suggests that consciousness isn’t ‘filtered’ sensory
information, but an active ‘conclusion’ drawn from information distributed
across senses, space and time.’ This is reflected by the paper’s own
theoretical assumptions, namely a Baars-style cognitivist account of
consciousness as a system for sharing information across agencies within the
brain.

If
Sergent’s experiment is valid, how can an enactivist account for conscious
experience if that experience is not the product of what the organism
encounters ‘right now’ but rather a synthesis of what the organism has experienced across
the last few hundred milliseconds? If class questions are anything to go by,
the Achilles’ heel of enactive theories of perception would seem to be in accounting for visual
experiences which occur in the absence of ‘the thing itself’ – for example
dreams, vivid memories, extreme hallucinations such as those that occur in
Charles Bonnett Syndrome.

It
could be said that these are aberrant or unusual phenomena. It can always be
argued that the ‘main thing’ is ordinary, wakeful, well-adjusted conscious
experience, and enactivism accounts well for most of that (while also having a
cursory stab at the other stuff too - I’m thinking here of Noe and O’Reagan’s
argument that the transient, shifting nature of dreamscapes indicates the
anchoring necessity of the world as its own best model. But still, how can
there be anything at all in dreams, even if what is there does fail to achieve
stability? Is it simply the harp randomly plucking its own sensorimotor
strings?). However, if retroperception (and thus the temporally ‘synthesised’ nature even
of everyday conscious experience, and presence within it of the 'no-longer-there' ) is confirmed by further testing, what
explanation could an enactivist offer? Would retroperception not indicate that
the cognitivist ‘mind/mind’ problem is a real one and not simply a theoretical
artefact, and that there is some kind of elaborate construction going on behind
the scenes?

Perhaps
the place to begin looking for an answer would be to ask what it is Sergent takes to be ‘conscious perception’. Mindhacks
might be too quick to use that magic word ‘consciousness’in the description above. From the paper,
there is no indication that participants ‘experienced’ the stimulus when
attention was post-cued to it; rather, similar to blindsight, they more
successfully reported the nature of the stimulus when given the attentional post-cues without actually reporting to
experience the stimulus. However, surely this still poses a problem for enactivists: if an
organism’s perceptions are directly experienced rather than providing
fodder for some internal model, how can there also be sensory detection without
experience?